For only the second time in Peyton Manning's career, the Colts are returning all 11 defensive starters. Add a healthy Bob Sanders and a newly signed Deshea Townsend to the mix, and Indy could open the season with the rare luxury of having 13 Super Bowl starters on the roster.

"It's so big because when you get a tight-knit group like ours, and mix it all together, you come to work ready to do your best," linebacker Clint Session said. "We play off one another and we want to get better."

Indy already knows it has a winning combination.

In Larry Coyer's first season as defensive coordinator, the defense ranked eighth in points allowed (19.2) and played a major part in helping the Colts reach their second Super Bowl in four years.

There's also plenty of room for improvement after yielding 126.5 yards rushing, 24th in the NFL; finishing in the middle of the league in sacks (34); and 15th in interceptions (16). Indy also had 92 defensive penalties, the most since 2005, and couldn't stop the Saints in the second half of the Super Bowl.

With one full season - and a second full offseason - to learn Coyer's aggressive system, the Colts have confidence and continuity.

"When you're on the field, just being comfortable with everyone goes a long way," defensive captain Gary Brackett said. "It goes right to the success of your team. I think we should develop a little more in the system, and it's like Coach (Tony) Dungy always said, the second year is when you increase your football IQ."

It's not just smoke and mirrors.

Indy, long known as an offensive powerhouse, has made a huge investment in its defense recently.

Five players - Brackett, Antoine Bethea, Dwight Freeney, Robert Mathis and Sanders - have signed contracts worth a combined $242.5 million since 2006. The deals for Sanders and Freeney also were the most lucrative at their position at the time.

Now the Colts are hoping it will pay off, though the tough part will be finding a spot for everyone.

Cornerbacks Jerraud Powers and Jacob Lacey combined to make 21 regular-season starts in 2009 and were impressive as rookies, but they'll vie for the starting job opposite Hayden. Whoever winds up as the backup may also have to contend with Townsend, a 12-year veteran, for playing time.

Bethea is coming off his second Pro Bowl season and just signed a $27 million contract, and former undrafted free agent Melvin Bullitt has established himself as a legitimate play-maker in Indy's secondary.

Coyer's job is devising ways to use Sanders and keep the big-hitting safety healthy. Sanders has started only eight regular-season games since being chosen as the 2007 NFL defensive player of the year, but has practiced all week. It's the first time Sanders hasn't opened training camp on the physically unable to perform list since 2007.

"He's our leader back there, and you could say he's the most battle-tested guy in the secondary," Hayden said. "He doesn't do a lot of talking, but when he leads, he leads by example and we need that."

The secondary isn't the only area making adjustments.

Indy's bookend pass rushers, Freeney and Mathis, both went to the Pro Bowl the last two seasons, rank first and second in sacks in franchise history and are No. 1 and No. 2 among all NFL players in forced fumbles since 2002.

If healthy, they won't lose any playing time.

But after taking another speedy pass rusher, Jerry Hughes, in the first round of this year's draft, the Colts are working on some new options.

Coach Jim Caldwell has said the Colts are experimenting with packages that would put all three on the field together. One possibility would make Hughes a standing rusher, a role the departed Raheem Brock played last season. Or Hughes could line up as a 3-4 linebacker, allowing the Colts to dial up more blitzes. Some teams actually projected Hughes as a linebacker.

All three linebackers - Brackett, Session and Philip Wheeler - are back, too, and second-round pick Pat Angerer will likely get some action behind Brackett in the middle.

What does it mean?

Well, the Colts believe this could be the defense that could bring them another Super Bowl crown.

"We've got guys who know what they're doing," Session said. "We're ready to make plays. We made a lot of plays last year, but we left a lot of plays, a lot of interceptions on the field, too. We definitely want to improve on all those areas this year, and we'll do whatever it takes to win games."